Adjustable slide members, especially to accomodate vehicle seat travel

ABSTRACT

An improved locking device comprising two assemblies relatively slidable with respect to each other, one of said assemblies having a support means extending in the direction of relative sliding and having thereon a first position holding means, the other of said assemblies having thereon a second position holding means for operative engagement with said first position holding means and biasing means attached to a toggle link means, said toggle link means being connected to said second position holding means for shifting it into and out of engagement with said first position holding means.

O United States Patent 1 3,66 1,352 McFarlane 1 May 9, 11972 54]ADJUSTABLE SLIDE MEMBERS, 3,310,274 3/1967. Tanaka et a1. ..248/430ESPECIALLY TO ACCOMODATE FOREIGN PATENTS 0R APPLICATIONS VEHICLE SEATTRAVEL 626,327 2/1936 Germany ..248/424 [72] Inventor: Arthur I-IerbertMcFarlane, Basildon, Env gland Primary Examiner-Milton KaufmanAttorney-John N. Bronaugh, Floyd S. Levison, E. Dennis O- [73] Assignee.Teleflex Limited, Basildon, Essex, England Connor and Richard A. Speer[22] Filed: June 4, I970 [21] Appl. No.: 43,480 [57] ABSTRACT Animproved locking device comprising two assemblies relatively slidablewith respect to each other, one of said assem- [30] Forms Apphcanonpnomy Dam blies having a support means extending in the direction ofJuly 10,1969 Great Britain ..34,872/69 relative Sliding and havingthereon first Position holding means, the other of said assemblieshaving thereon a second 52 u.s.c1.... Y ..248/429, 74 533 Positionholding means for Operative engagement with Said [51] Int. Cl ..Fl6m13/00 first Position holding means and biasing means attached to a 58Field 61 Search ..74/536, 537, 533,529, 527; toggle link means. saidtoggle link means being connected to 243 424 429 430 said secondposition holding means for shifting it into and out of engagement withsaid first position holding means. [56] References cued 10 Claims, 4Drawing Figures UNITED STATES PATENTS 2,951,527 9/1960 Wassileff..248/430 X ADJUSTABLE SLIDE MEMBERS, ESPECIALLY TO ACCOMODATE VEHICLESEAT TRAVEL This invention relates to the locking of adjustable slidemembers. More particularly, it is concerned with locks for slides insituations where a positive locking action is important to enable theslide to sustain possible occasional high loading, for example in anemergency. Such a situation is found in the case of seat travel oradjustment slides for vehicle seats, where crash loads should be takeninto consideration.

A conventional way of positively locking seat slides is to providewithdrawable pinsthat can engage in a selection of holes. This system,however, has drawbacks, especially inhigh duty applications, forinstance, aircraft crew seats. It is therefore an object of thisinvention to provide a more reliable and satisfactory arrangement.

According to the present invention, one of two relatively slidingassemblies has a bar extending in the direction of relative sliding andbearing rack-type teeth for engagement by a toothed lock 'member on theother assembly, which lock member is shiftable into and out ofengagement with the rack teeth by spring-loaded toggle links. In thepreferred arrangement, two such toothed locked members are provided atspaced positions along the bar, for safety, to provide dual load paths,and minimize any tendency of the sliding assembly to skew due to singlepoint application of the lock.

One arrangement in accordance with the invention is shown by way ofexample in the accompanying drawings. The embodiment illustrated is onelock of an aircraft crew seat that is mounted for sliding horizontaltravel. In the drawings:

FIG. 1 is a plan view of the lock,

FIG. 2 is a view in section on the line 22 of FIG. 1,

FIG. 3 is a further plan showing the locking parts in a differentoperative position and the associated seat rail, the top plate of thelock being removed, and

FIG. 4 is a view on the line 4-4 of FIG. 3.

The seat is mounted for positional adjustment fore and aft along a trackcomprising rails bolted to the aircraft floor. A horizontal bar 11extending in the direction of seat travel forms an integral sideportion'of one of the track rails over which the seat slides. Twosimilar lock assemblies 12, only one of which is shown, are mounted onthe seat alongside the bar 11 and spaced in the direction of travel. Thebar 11 has laterally facing rack-type teeth 13 and each lock assembly 12includes a lock lever 14 with teeth 15 to engage with the teeth on thebar and thereby effect locking.

The lock lever 14 extends horizontally approximately in a directionparallel to the bar 11 and it has a head at one end bearing the teeth 15while at an intermediate point along its length it is pivotally mountedbetween upper and lower plates of a lock housing 16 by means of a pin17. Beyond the pivot, the lock lever is extended to form aswitch-operating tail 18. A toggle linkage 19, 20 operates in ahorizontal plane and, when straightened, is generally at right angles tothe bar 11. The toggle linkage has a common pivot or articulation point21 and two outer pivots 22, 23, the pivot 22 being received by the headof the lock lever 14 while the pivot 23 is journaled in the plates ofthe housing 16. Straightening of the toggle linkage urges the head ofthe lock lever into locking engagement with the teeth of the bar 11,while "breaking of the toggle retracts the locking lever head from thebar.

Pivotally connected to the toggle linkage at the articulation point 21is an eye-piece 24 on one end of a sliding rod 25 that is surrounded bya compression spring 26. The spring bears at one end on a disc 27,backed up by a stop 28 in the housing, and at the other end on a disc 29on the eye-piece 24, whereby the toggle linkage 19, 20 is urged by thespring loading toward the straightened condition. For breaking thetoggle linkage and retracting the lock lever head against the springaction, the toggle link 20 is extended beyond its pivot 23 to provide alock release lever 30. The two release levers 30 on the toggle linkagesof the two lock assemblies are ganged to operate together.

To prevent the toggle linkage going over-center a stop 31 is providedbetween the housing plates 16. This stop also serves to check theretraction movement of the lock lever 14 by engaging a recess 32 in thelock lever head. The tail 18 of the lock lever actuates a miniatureswitch 33, mounted between the housing plates 16, to indicate when thelock is engaged.

The provision of two lock assemblies 12 not only prevents the skewing ofthe sliding assembly that might occur with only one but also is a safetymeasure in that each lock is capable of taking the total load, ifnecessary. As a precaution against the lock lever pivot pin 17 breaking,the lock lever in each lock is shaped so that, when the lock is engaged,it embraces a shoe or stop 34 fixed between the housing plates 16.Should the pin 17 give way, the lock lever will abut the shoe 34 thusarresting endwise movement. Another safety measure is that the toothedbar 11 is split longitudinally on a plane bisecting the teeth into twoparts 11a, 11b, either of which is capable of taking the full loading.

What I claim is:

1. An improved locking device comprising two assemblies relativelyslidable with respect to each other, one of said assemblies having asupport means extending in the direction of relative sliding and havingthereon a first position holding means, the other of said assemblieshaving thereon at least one second position holding means for operativeengagement with said first position holding means and biasing meansattached to a toggle link means, said toggle link means beingoperatively connected to said second position holding means for shiftingit into and out of engagement with said first position holding means.

2-. The locking device, as claimed in claim 1, wherein said firstposition holding means includes a first toothed member and said secondposition holding means includes a second toothed member.

3. A locking device as claimed in claim 2 wherein said support meanscomprises two support members in a side by side relation, each of saidsupport members being capable of independently sustaining a full loadingapplied by said second toothed member.

4. The locking device, as claimed in claim 1, wherein said biasing meansincludes a spring which biases said toggle link means to a positionholding condition.

5. The locking device, as claimed in claim 1, wherein said toggle linkmeans further comprises release lever means for moving said toggle linkmeans against the action of said biasing means to disengage said secondposition holding means from said first position holding means.

6. The locking device, as claimed in claim 1, wherein saidother'assembly includes a housing on which said toggle link means andsecond position holding means are mounted, said housing being movable ina horizontal plane along one side of said support means which forms anintegral portion of a floor mounted running rail.

7. A locking device as claimed in claim 8 further including an electricswitch mounted on said other assembly for actuation by the shifting ofsaid second position holding means.

8. A locking device as claimed in claim 1 wherein the second positionholding means is pivotally connected to a housing, said housing having astop member secured thereto and adapted to engage a portion of saidsecond position holding means during its engagement with said firstposition holding means, said stop member being further adapted toprevent slidable movements of said assemblies should said pivotalconnection malfunction.

9. A locking device as claimed in claim 1 wherein two spaced apartsecond position holding means engage said first position holding means.

10. A locking device as claimed in claim 9 further comprising meansoperatively interconnecting said two spaced apart second positionholding means for shifting said two second position holding means inunison into and out of engagement with said first position holdingmeans.

52 33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,661,352Dated May 9,' 1972 ARTHUR H. MCFARLANE Patent No.

Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 54 (Claim 7), change the numeral "8" to the numeral "1''.

Signed and sealed this 6th day of February 1973..

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSGHALK Attesting Officer Commissionerof Patents

1. An improved locking device comprising two assemblies relativelyslidable with respect to each other, one of said assemblies having asupport means extending in the direction of relative sliding and havingthereon a first position holding means, the other of said assemblieshaving thereon at least one second position holding means for operativeengagement with said first position holding means and biasing meansattached to a toggle link means, said toggle link means beingoperatively connected to said second position holding means for shiftingit into and out of engagement with said first position holding means. 2.The locking device, as claimed in claim 1, wherein said first positionholding means includes a first toothed member and said second positionholding means includes a second toothed member.
 3. A locking device asclaimed in claim 2 wherein said support means comprises two supportmembers in a side by side relation, each of said support members beingcapable of independently sustaining a full loading applied by saidsecond toothed member.
 4. The locking device, as claimed in claim 1,wherein said biasing means includes a spring which biases said togglelink means to a position holding condition.
 5. The locking device, asclaimed in claim 1, wherein said toggle link means further comprisesrelease lever means for moving said toggle link means against the actionof said biasing means to disengage said second position holding meansfrom said first position holding means.
 6. The locking device, asclaimed in claim 1, wherein Said other assembly includes a housing onwhich said toggle link means and second position holding means aremounted, said housing being movable in a horizontal plane along one sideof said support means which forms an integral portion of a floor mountedrunning rail.
 7. A locking device as claimed in claim 8 furtherincluding an electric switch mounted on said other assembly foractuation by the shifting of said second position holding means.
 8. Alocking device as claimed in claim 1 wherein the second position holdingmeans is pivotally connected to a housing, said housing having a stopmember secured thereto and adapted to engage a portion of said secondposition holding means during its engagement with said first positionholding means, said stop member being further adapted to preventslidable movements of said assemblies should said pivotal connectionmalfunction.
 9. A locking device as claimed in claim 1 wherein twospaced apart second position holding means engage said first positionholding means.
 10. A locking device as claimed in claim 9 furthercomprising means operatively interconnecting said two spaced apartsecond position holding means for shifting said two second positionholding means in unison into and out of engagement with said firstposition holding means.